/Engine/Plugins/Experimental/MeshModelingToolsetExp/Source/SkeletalMeshModifiers/Public/SkinWeightModifier.h
Remove all weights below the given threshold value, on all vertices.
true if influences were removed, false otherwise
[UFUNCTION](Programming/UnrealArchitecture/Reference/Functions)(BlueprintCallable, Category="Weights") bool PruneAllWeights ( const float WeightThreshold )